A biradical oxo-molybdenum complex containing semiquinone and o-aminophenol benzoxazole-based ligands

We report a new mononuclear molybdenum(iv) complex, MoOL^BISL^SQ, in which L^SQ (2,4-di-tert-butyl o-semibenzoquinone ligand) has been prepared from the reaction of the o-iminosemibenzoquinone form of a tridentate non-innocent benzoxazole ligand, L^BIS, and MoO₂(acac)₂. The complex was characterized by X-ray crystallography, elemental analysis, IR and UV-vis spectroscopy and magnetic susceptibility measurements. The crystal structure of MoOL^BISL^SQ revealed a distorted octahedral geometry around the metal centre, surrounded by one O and two N atoms of L^BIS and two O atoms of L^SQ. The effective magnetic moment (μ_eff) of MoOL^BISL^SQ decreased from 2.36 to 0.2 μ_B in the temperature range of 290 to 2 K, indicating a singlet ground state caused by antiferromagnetic coupling between the metal and ligand centred unpaired electrons. Also, the latter led to the EPR silence of the complex. Cyclic voltammetry (CV) studies indicate both ligand and metal-centered redox processes. MoOL^BISL^SQ was applied as a catalyst for the oxidative cleavage of cyclohexene to adipic acid and selective oxidation of sulfides to sulfones with aqueous hydrogen peroxide.

Biradical molybdenum(iv) complex, MoOL^BISL^SQ, has been prepared from the reaction of the o-iminosemibenzoquinone form of a tridentate non-innocent benzoxazole ligand, L^BIS, and MoO₂(acac)₂ and used as catalyst in oxidation reaction..     

Beneficial effect of a multimerized immunoglobulin Fc in an animal model of inflammatory neuropathy (experimental autoimmune neuritis)

Intravenous immunoglobulin (IVIg) is one of the first‐line therapies for inflammatory neuropathies. Clinical use of IVIg for these disorders is limited by expense and availability. Here, we investigated a synthetic product alternative to IVIg. The aim of this study was to test the therapeutic efficacy of a novel recombinant polyvalent murine IgG2a Fc compound (stradomer?) in experimental autoimmune neuritis (EAN). Seventy‐four Lewis rats were immunized with myelin, randomized into three groups, and were treated with albumin, IVIg, or stradomer at 1% of IVIg dose. Rats were assessed clinically, electrophysiologically, and histologically. The clinical disease severity was evaluated by clinical grading and weight changes. The electrophysiological studies recorded motor conduction velocity (MCV), amplitudes, and latencies of the evoked compound muscle action potential (CMAP) and spinal somatosensory evoked potential. The treatment efficacy of the IVIg and stradomer groups was compared to the albumin (control) group. We demonstrate that stradomer has a similar therapeutic efficacy to human IVIg in EAN. Rats receiving stradomer or IVIg showed significantly lower clinical scores and less prominent weight loss compared with controls. A statistically significant improvement in both MCV and the amplitudes of distal and proximal evoked CMAP was observed in the stradomer and IVIg groups. Finally, treatment with both IVIg and stradomer resulted in statistically less inflammation and demyelinating changes in the sciatic nerve as evidenced by lower histological grade. These results reveal the potential of using fully recombinant multimerized immunoglobulin Fc instead of IVIg for treating inflammatory neuropathies.     

A Comparative Study of Crestal Bone Loss and Implant Stability between Osteotome and Conventional Implant Insertion Techniques: A Randomized Controlled Clinical Trial Study

Purpose: The aim of this prospective randomized controlled clinical study was to assess the crestal bone loss and the implant stability in implants that were placed by the osteotome technique compared with the conventional drilling technique. Materials and Methods: Forty‐six screw type Straumann SLA® oral implants (Straumann AG, Waldenburg, Switzerland) were inserted in the anterior segment of maxilla of 30 patients. The implant site was prepared randomly using either osteotome technique (test group) or the conventional drilling technique (control group). Radio frequency analysis (RFA) values at implant placement and after 3 months were recorded. The crestal bone loss was measured using digital subtraction radiography technique after 3, 6, and 12 months. Results: RFA demonstrated a statistically significant higher primary stability for implants in the osteotome group than that of the conventional group (p = .026) at the time of implant insertion. However, there was no statistically significant difference between both groups 3 months after the surgery (p = .06). At month 3, the osteotome group caused significantly more crestal bone loss than the conventional group (p = .04). At months 6 and 12, both groups had comparable bone levels (p = .29). Conclusion: Osteotome technique yielded higher primary stability than conventional drilling technique. However, this technique was not superior to conventional technique after 3 months.     

Safety and Efficacy of Phenylephrine Nasal Drops in Bronchiolitis

Objective: Bronchiolitis is a common lower respiratory tract infection in the first year of life. In this disease upper respiratory tract infection is associated with nasal congestion, respiratory distress and hypoxia. We studied the effect of phenylephrine drops as a decongestant in treatment of light and moderately severe cases of acute bronchiolitis. Methods: This is a double blind randomized trial involving 100 children aged 4 weeks to 12 months. The patients were divided into two groups, the first group received 0.1 ml phenylephrine 0.5% and the second group 0.1 ml sodium chloride (NaCl) 0.9% as placebo in both nostrils. Respiratory rate, heart rate, O2 saturation, dyspnea, retractions and wheezing were assessed before and 30 minutes after medication. Findings: After medication, O2 saturation and respiratory muscles retractions in the phenylephrine group were significantly better than those of the placebo group (P=0.004 and P=0.002, respectively). In the phenylephrine group, O2 saturation, retractions and wheezing were also significantly better before than those after medication (P=0.003 and P<0.0001 respectively). In the placebo group no significant difference before and after intervention was observed. Conclusion: Phenylephrine as a topical decongestant is an inexpensive, easily available and suitable means in the treatment of mild to moderately severe bronchiolitis.Key Words: Respiratory Tract, Bronchiolitis, Alpha Agonist, Phenylephrine     

Accuracy of Implant Impressions with Different Impression Coping Types and Shapes

Background: Accurate recording of implant location is required so that definitive restorations are properly supported and do not place additional stresses on the implants. Movement of impression copings inside the impression material using an open‐tray or close‐tray impression technique during clinical and laboratory phases may cause inaccuracy in transferring the three‐dimensional spatial orientation of implants intraorally to the definitive cast. Consequently, the restoration may require corrective procedures. Aim: This in vitro study compared the accuracy of two different impression techniques with two different impression coping shapes using polyether impression material to obtain precise definitive casts. Materials and Methods: Two reference acrylic resin models (Technovits 4000, Heraeus Kulzer GmbH & Co., Wehrheim, Germany) with five internal connection implants having different shapes of impression copings (Implantium [Dentium, Seoul, South Korea] and Replace Select [Nobel Biocare AB, Göteborg, Sweden]) were fabricated. Twenty medium‐consistency polyether impressions of these models were made with square and conical impression copings of each system using open‐tray and close‐tray techniques. Matching implant replicas were screwed into the impression copings in the impressions. Impressions were poured with type IV stone, and the positional accuracy of the implant replica heads in x‐, y‐, and z‐axes (represented in [Δr]) and also rotational displacement (ΔΘ) were evaluated using a coordinate measuring machine (Mistral, DEA Brown&Sharpe, Grugliasco, Italy). These measurements (linear and rotational displacements) were compared with the measurements calculated on the reference resin models that served as control, and data were analyzed with a two‐way analysis of variance at α = 0.05. Results: Less inaccuracy occurred in less retentive shape impression copings (Replace Select) compared with the more retentive one (Implantium) (p_r < .001 and p_Θ < .001), but there was no significant difference between direct and indirect impression techniques (p_r and p_Θ > .05). Conclusion: The impression coping shape had more impact on impression inaccuracy than impression technique did. Understanding of the magnitude and variability of distortion when employing certain impression‐making methods and impression coping shapes helps the clinician to select a better implant component and impression technique.     

Interaction of cellulose and nitrodopamine coated superparamagnetic iron oxide nanoparticles with alpha-lactalbumin

In recent years, numerous studies have focused on the understanding of the interactions between proteins and nanoparticles (NPs). In this work, we focus on the interaction of bovine α-lactalbumin (BLA) with differently coated magnetic nanoparticles (MP): as formed MP, MPs stabilized with dopamine (MP_dopamine) and nanoparticles coated with cellulose (MP_cellulose). The influence of the coating on the nanoparticle–protein interaction is revealed by a set of different experiments. The binding affinity (K_A) between BLA and these three structures was found to vary from 10⁵ M⁻¹ (for MPs) to 10¹¹ M⁻¹ (MP_cellulose). The orientation of BLA and the involvement of amino acid residues in the process of interaction with magnetic nanoparticles were identified by molecular docking studies. In addition, circular dichroism spectra revealed that the conformation of BLA was conserved upon interaction with the magnetic nanoparticles.

The adsorption of BLA on the SPIOns, and their non-toxic nature of the bioconjugate make these nanoparticles new model nanostructures for nanomedicine orientated applications.